Silicia Nanoparticles for Enhancing the Performance of Waterflooding in Oil Reservoirs

Silica nanoparticles (SNPs) have been widely utilized in the oil and gas industry to improve different processes, such as in drilling operations, well cementing job, workover operations, wastewater remediation, and most importantly enhance oil recovery. Due to their particle sizes which ranges between 1 and 100 nm, large specific surface area, high dispersibility and tunable physico-chemical properties, they have the capability to alter the wettability of the reservoir rock and reduce the interfacial tension between crude oil and brine phases. The implementation of functionalized SNPs in oil recovery processes with amino cationic surfactants has not
been well evaluated. This work was aimed at functionalizing the surface of SNPs with (3-aminopropyl) triethoxysilane (APTES) to increase its dispersion stability, alter the wettability of the rock in an oil drop experiment, reduce the IFT between oil and
water using the ring method and to increase the oil recovery using water injection in a glassbeads flooding setup. The functionalization was confirmed with the identification of functional groups using FTIR, surface morphology changed as viewed under FESEM and the elemental composition with additional nitrogen and carbon as confirmed by EDX. The particle size distribution was equally observed to
be better after the modification. The stability was confirmed by zeta potential analysis to improve from -16 mV to +26.4 mV after modification, and the contact angle equally changed from 44.4ºto 125.5º. The IFT value of 8.5mN/m was able to be achieved for CMC at 1.8 %wt. and 75% of the oil initially in place was able to be recovered. APTES modified the surface of SNPs through the deposition of its
molecules on the surface of negatively charged hydroxyl (-OH) groups of the SNPS, which gave rise to electrostatic attraction forces between the negative particles and APTES particles. This will enhance dispersion stability and subsequently improve oil recovery

TABLE OF CONTENTS
UNIVERSITI TEKNOLOGIMALAYSIA iii
DECLARATION iii
DEDICATION iv
ACKNOWLEDGEMENT v
ABSTRACT vi
ABSTRAK vii
LIST OF ABBREVIATIONS xii
CHAPTER 1 INTRODUCTION 1
1.1 Background of study 1
1.2 Problem Statement 4
1.3 Objectives 6
1.4 Scope of The Study 6
1.5 Significance of the study 7
CHAPTER 2 LITERATURE REVIEW 9
2.1 Introduction 9
2.2 Oil Recovery Processes 9
2.3 Chemical Oil Recovery Processes 10
2.4 Waterflooding 14
2.5 Oil Displacement Mechanism by Waterflooding 15
2.6 Factors Governing Macroscopic Sweep Efficiency 16
2.6.1 Wettability Alteration 17
2.6.2 Interfacial Tension Reduction 19
2.7 Silica Nanoparticles 20
2.8 (3-Aminopropyl) triethoxysilane 21
2.9 Surface Modification of Silica Nanoparticles 22
2.9.1 Effects of APTES- Modified Silica Nanoparticles
2.10 Preparation of Silica Nanoparticles 24
2.10.1 Impact of Nanofluid on Oil Viscosity 25
2.10.2 Stability evaluation methods for Nano fluids 25
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2.10.3 Method of Sedimentation 26
2.10.4 Method of Centrifugation 26
2.10.5 Method of Spectral Analysis 27
2.10.6 Omega Method 27
2.10.7 Light Scattering Microscopy and Electron Method 27
2.10.8 Zeta Potential Analysis 28
2.11 Importance of Surfactants in Nanofluids for Oil Recovery 29
2.12 The Impact of Reservoir Temperature on the Recovery of Oil 29
CHAPTER 3 METHODOLOGY 31
3.1 Introduction 31
3.2 Materials 33
3.3 Methods and Procedures 33
3.3.1 Nanosilica surface modification 33
3.3.2 Characterisation of Modified Nanosilica 34
3.3.3 Preperation of Brine solution 34
3.3.4 Preparation of Nanofluid 34
3.3.5 Preparation of SNPS-APTES system 35
3.3.6 Interfacial Tension Determination 35
3.3.7 Wettability Test 36
3.3.7 Colloidal Stability Test 36
3.3.8 Flooding Test 37
CHAPTER 4 RESULTS AND DISCUSSIONS 39
4.1 Introduction 39
4.2 Characterisation of APTES Modified Silica Nanoparticles 39
4.2.1 Fourier Transform Infrared Spectroscopy (FTIR) 39
4.2.2 Field Emission Scanning Electron Microscopy(FESEM) 41
4.2.2 Particle Size Distribution and Stability 42
4.2.3 Zeta Potential Analysis 44
4.3 Wettability Analysis 45
4.4 Interfacial Tension (IFT) Analysis 47
4.5 Glass Beads Flooding Analysis 48
CHAPTER 5 CONCLUSION AND RECOMMENDATION 49
5.1 Conclusion 49
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REFERENCES 51
APPENDIX A 61
Table A. 2. Determination Of Pore Volume 63
Table A.2 (3–Amino Propyl) Triethoxysilane (Aptes) Of 97 % Reagent Grade 65